Highway Engineering Multiple Choice Questions on “Traffic Flow and Roadway Capacity”.

1. The weaving manoeuvres is a type of __________
a) Merging
b) Diverging
c) Intersection
d) Crossing
Clarification: The weaving manoeuvre is a type of crossing manoeuvre as it involves crossing of traffic.

2. Which of the following does not affect traffic flow?
a) Vehicles travelling at speed
b) Length of the vehicle
c) Weather conditions
d) Geometric design
Clarification: Traffic flow does not depend on the length of the vehicle, as it is not related to the flow.

3. The speed at which the value of time headway is lowest represents the __________
a) Optimum speed
b) Maximum speed
Clarification: The speed at which the value of time headway is lowest represents the optimum speed.

4. In countries like USA and UAE, which of the regulation is followed?
a) Keep to left
b) Keep to right
c) Keep to middle
Clarification: In countries like US and UAE, keep to right regulation is followed as they follow the left hand drive.

5. When the gap of the vehicle changes to a smaller lane then it is called __________
a) Lane change
b) Forced lane change
c) Simultaneous lane change
d) Voluntary lane change
Clarification: The gap of the vehicle changes to a smaller lane then it is called as forced lane change, as it forces a driver to shift to the smaller lane.

6. The vehicles per unit length at any instant of time is called as __________
a) Density
b) Jam density
c) Maximum density
d) Traffic flow
Clarification: At any instant of time, the vehicles per unit length are called as density, if traffic speed is zero then it is called jam density.

7. The distance between the two consecutive vehicles is called __________
c) Jam density
d) Traffic flow
Clarification: The distance between the two consecutive vehicles is called as space headway, and it is measured from head to head of the vehicle.

8. The maximum jam density occurs at __________
a) Zero speed
b) 15th percentile speed
c) 30th percentile speed
d) 98th percentile speed
Clarification: The maximum jam density occurs at zero speed, which indicates that there is no movement of vehicles and the density is maximum.

9. If the space headway is 7m, then the jam density in vehicle/km is __________
a) 142
b) 144
c) 145
d) 146
Clarification: Ki=1000/7
Ki=142 vehicles/km.

10. The minimum space headway increases with __________
a) Increase in length of vehicle
b) Increase in width of vehicle
c) Increase in weight of vehicle
d) Increase in width of pavement
Clarification: The minimum space headway increases with the length of the vehicle, if the length is more then the headway will be more.

11. Which of the following equation is correct?
a) Q=KV
b) K=qv
c) K=qv2
d) V=kq
Clarification: K is the density of vehicles/km and V is the velocity in kmph Q is the number of vehicles.

12. The maximum jam density occurs at __________
a) Ki
b) Ki/2
c) Ki/3
d) Ki/4
Clarification: The maximum jam density occurs at Ki=Ki/2 and Vs = Vsf/2.

13. If the jam density is 145vehicles/km, and velocity is 60kph then the capacity flow is __________
a) 2175
b) 2200
c) 2375
d) 2500
Clarification: Capacity flow=145*60/4
=2175 vehicles per lane.

14. The equivalency factor for the car recommended by IRC is?
a) 0.5
b) 1.0
c) 1.5
d) 2.0